BAR plot bug - an additional patch

I am plotting datasets using BAR, let say like that:

bar(edges, hy(:, jj), mycolor, 'stacked','BarWidth',1, 'ShowBaseLine', 'off', 'Parent', hh);

when mycolor is different from 'flat' (e.g. 'blue' ) I experience a strange patch of the came color connecting top of each bar with left-bottom corner of axis and abscissa (triangle). The fun part it is not always like that for the same code and different data. Ideas ?

[Matt Kindig]

Can you post some sample data for 'edges', 'hy', 'mycolor' so that we can try to reproduce your problem?